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Why Switch From Pure DI-Water To Chemistry?

Description: While most cleaning processes in the worldwide market still rely on cleaning with DI-water only (for OA flux removal), recent studies suggest that water is beginning to reach its cleaning limitation, favoring the use of chemically assisted cleaning processes. The increased use of water-soluble lead-free solder requires more activators and higher soldering temperatures which result in more burnt in fluxes to produce water insoluble contamination. DI-water alone has a limited to no ability to solubilize non-ionic residues on the board surface.

These findings coincide with the use of smaller, more densely packed components which further limits pure DI-water to be effective. Water with its high surface tension of over 70 dynes/cm cannot effectively penetrate underneath low standoff components. Chemistry assisted cleaning can reduce the surface tension to 30 dynes/cm and below.

This technical presentation highlights the authors' initial in-house findings, which were based on a full factorial DOE study. The findings revealed significant experimental data, which sheds much needed light on this emerging industry challenge. They include but are not limited to data related to: